When storing your Yamaha outboard motor for prolonged periods of time (2 months or longer), several important procedures must be performed to prevent excessive damage. It is advisable to have your outboard motor serviced by an authorized Yamaha dealer prior to storage. However, you, the owner, with a minimum of tools, can perform the following procedures.


  • Do not place the outboard motor on its side before the cooling water has drained from it completely, otherwise water may enter the cylinder through the exhaust port and cause engine trouble.
  • Store the outboard motor in dry, well ventilated place, not in direct sunlight.

Flushing in a Test Tank



Do not run the engine without supplying it with cooling water.  Either the engine water pump will be damaged or the engine will be damaged from overheating. Before starting the engine, be sure to supply water to the cooling water passages.

1. Wash the outboard motor body using fresh water. NOTICE: Do not spray water into the air intake. For further information.

2. Fill the fuel tank with fresh fuel and add one ounce of “Yamaha Fuel Conditioner and Stabilizer” to each gallon of fuel.

The use of “Yamaha Fuel Conditioner and Stabilizer” eliminates the need to drain the fuel system. Consult your Yamaha dealer of other qualified mechanic if the fuel system is to be drained instead.

3. Remove the engine top cowling and silencer cover.

4. Install the outboard motor on the test tank.

5. Fill the tank with fresh water to above the level of anti-cavitation plate.NOTICE: If the fresh water level is below the level of the anti-cavitation plate or if the
water supply is sufficient, engine seizure may occur.

6. Cooling system flushing is essential to prevent the cooling system from clogging up with salt, sand, or dirt. In addtion, fogging of the engine is mandatory to prevent excessive engine damage due to rust. Perform the flushing and fogging at the same time.
WARNING!Do not touch or remove electrical parts when starting or during operation. keep hands, hair and clothes away from the flywheel and other rotating parts while the engine is running.

7. Run the engine at a fast idle for 10-15 minutes in neutral position.

8. Just prior to turning off the engine, quickly spray ” Yamaha Stor-Rite Engine Fogging Oil ” alternately into each carburetotr or the fogging hole of the silence cover, it equipped. When properly done, the engine will smoke excessively and almost stall.

9. Remove the outboard motor from the test tank.
10. Drain the cooling water completely out of motor. clean the body thoroughly.

11. Install the silencer cover/cap and top cowling.